The Lost River actress, 42, wore a flowery maxi dress and pulled her brunette locks up in a messy bun. She kept her belly hidden by holding an oversized brown bag and a peacoat close to her body.
That same day, Us Weekly exclusively broke the news that Mendes and Gosling, 35, are expecting their second child together. A source told Us that the actress previously tried to conceal her bump during an L.A. photo shoot back in February.
Mendes and the Nice Guys star began dating after meeting on set of The Place Beyond the Pines in 2011. Us exclusively confirmed that they welcomed their daughter, Esmeralda, now 19 months, in September 2014.
Mendes opened up about motherhood during an interview with Women's Health in March 2015. "I’m actually enjoying the sleepless nights because it’s bonding with my little girl," she said at the time.
She joked: "I don’t feel like I’ve really earned the right [to give motherly advice]. I want to respect all the moms out there. They’re going to be like, ‘You know what? You’re a few months in. Just shut up.'"
Mendes and Gosling have been very private about their family from the start. Gosling, however, did gush over his leading lady back in December.
"I know that I’m with the person I’m supposed to be with," he told Hello magazine. He added that the only quality he looks for in a woman is "that she’s Eva Mendes."
He mused: "There's nothing else I’m looking for."
Can't get enough of Us? Sign up now for the Us Weekly newsletter packed with the latest celeb news, hot pics and more!